Listen, and hear of their gallantry -- often outnumbered and outgunned -- in some of the most brutal combat in modern history. How they held the line at the Pusan Perimeter. How they landed at Inchon and turned the tide of the war. How, surrounded and freezing, they battled their way out of Chosin Reservoir. And how they fought -- foxhole by foxhole, mountain after mountain, day and night -- at the Punchbowl and Heartbreak Ridge, Old Baldy and Pork Chop Hill.

They dwell on effects and modifications, without tracing them back to causes; and complicated rules to adjust behaviour are a weak substitute for simple principles.